Exploring the raison d'etre behind metric selection in network analysis: a systematic review

Network analysis is a useful tool to analyse the interactions and structure of graphs that represent the relationships among entities, such as sectors within an urban system. Connecting entities in this way is vital in understanding the complexity of the modern world, and how to navigate these complexities during an event. However, the field of network analysis has grown rapidly since the 1970s to produce a vast array of available metrics that describe different graph properties. This diversity allows network analysis to be applied across myriad research domains and contexts, however widespread applications have produced polysemic metrics. Challenges arise in identifying which method of network analysis to adopt, which metrics to choose, and how many are suitable. This paper undertakes a structured review of literature to provide clarity on raison d'etre behind metric selection and suggests a way forward for applied network analysis. It is essential that future studies explicitly report the rationale behind metric choice and describe how the mathematics relates to target concepts and themes. An exploratory metric analysis is an important step in identifying the most important metrics and understanding redundant ones. Finally, where applicable, one should select an optimal number of metrics that describe the network both locally and globally, so as to understand the interactions and structure as holistically as possible.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s41109-022-00476-w.

Proceedings of the Canadian Thyroid Cancer Active Surveillance Study Group 2019 national investigator meeting

Abstract

Active surveillance (AS) in the management of small, low risk papillary thyroid cancer (PTC) as an alternative option to thyroidectomy, is an area of active research. A national Canadian study is proposed to evaluate the long-term outcomes of patients with small, low risk PTC who choose AS or surgery. This letter describes the proceedings of a national investigator meeting to plan the study.

Graphical abstract

A Protocol for a Pan-Canadian Prospective Observational Study on Active Surveillance or Surgery for Very Low Risk Papillary Thyroid Cancer

Background

The traditional management of papillary thyroid cancer (PTC) is thyroidectomy (total or partial removal of the thyroid). Active surveillance (AS) may be considered as an alternative option for small, low risk PTC. AS involves close follow-up (including regularly scheduled clinical and radiological assessments), with the intention of intervening with surgery for disease progression or patient preference.

Methods

This is a protocol for a prospective, observational, long-term follow-up multi-centre Canadian cohort study. Consenting eligible adults with small, low risk PTC (< 2cm in maximal diameter, confined to the thyroid, and not immediately adjacent to critical structures in the neck) are offered the choice of AS or surgery for management of PTC. Patient participants are free to choose either option (AS or surgery) and the disease management course is thus not assigned by the investigators. Surgery is provided as usual care by a surgeon in an institution of the patient's choice. Our primary objective is to determine the rate of 'failure' of disease management in respective AS and surgical arms as defined by: i) AS arm - surgery for progression of PTC, and ii) surgical arm - surgery or other treatment for disease persistence or progression after completing initial treatment. Secondary outcomes include long-term thyroid oncologic and treatment outcomes, as well as patient-reported outcomes.

Discussion

The results from this study will provide long-term clinical and patient reported outcome evidence regarding active surveillance or immediate surgery for management of small, low risk PTC. This will inform future clinical trials in disease management of small, low risk papillary thyroid cancer.

Registration details

This prospective observational cohort study is registered on clinicaltrials.gov (NCT04624477), but it should not be considered a clinical trial as there is no assigned intervention and patients are free to choose either AS or surgery.

Using cross-sectoral data linkage to understand the health of people experiencing multiple exclusion

Background

People affected by the intersection of homelessness, drug use, and/or serious mental illness have high rates of mortality and morbidity. However, they are often missed from routine information sources on population health, such as surveys and censuses. In many countries, administrative data are available which could help address this knowledge gap. We created a novel virtual cohort using cross-sectoral data linkage in order to inform policy and practice responses to these co-occurring issues.

Methods

Individual-level data from local authority homelessness services (HL), opioid substitution therapy dispensing (OST), and a psychosis case register (PSY) in Glasgow, Scotland between 2011-15 were confidentially linked to National Health Service records, using a mix of probabilistic and deterministic linkage. A de-identified dataset was made available to researchers through a secure analysis platform. Demographic characteristics associated with different exposure combinations were analysed using descriptive statistics.

Results

Linkage created a cohort of 24,767 unique individuals with any one of the experiences of interest between 2011-15. Preliminary results suggest that 89.2% of the cohort had one experience; 10.6% two; and 0.2% all three. The most common combination was HL & OST (n = 2,150; 8.7%), with other combinations much less frequent (HL & PSY, n = 279, 1.1%; OST & PSY, n = 188, 0.8%; HL & OST & PSY, n = 51, 0.2%). The odds of male gender increased with number of exposures (2 exposures, OR 2.1, 95% CI 1.9-2.2; 3 exposures, OR 4.1, 95% CI 2.3-7.2), but there was little difference in age. Work is ongoing to incorporate into the cohort additional datasets on criminal justice involvement.

Lessons

Administrative data linkage is a feasible approach to understanding the health of people affected by multiple exclusionary processes, but requires robust and timely governance. Our initiative can support service planning and evaluation of future policy or service changes.

Key messages

We describe the creation and characteristics of a novel virtual cohort of people affected by multiple exclusionary processes, using record linkage of administrative datasets. Cross-sectoral linkage has international potential for enhancing public health intelligence, especially for population groups who may be missed from surveys and censuses.

Genomes reveal genetic diversity of Piscine orthoreovirus in farmed and free-ranging salmonids from Canada and USA

Piscine orthoreovirus (PRV-1) is a segmented RNA virus, which is commonly found in salmonids in the Atlantic and Pacific Oceans. PRV-1 causes the heart and skeletal muscle inflammation disease in Atlantic salmon and is associated with several other disease conditions. Previous phylogenetic studies of genome segment 1 (S1) identified four main genogroups of PRV-1 (S1 genogroups I–IV). The goal of the present study was to use Bayesian phylogenetic inference to expand our understanding of the spatial, temporal, and host patterns of PRV-1 from the waters of the northeast Pacific. To that end, we determined the coding genome sequences of fourteen PRV-1 samples that were selected to improve our knowledge of genetic diversity across a broader temporal, geographic, and host range, including the first reported genome sequences from the northwest Atlantic (Eastern Canada). Nucleotide and amino acid sequences of the concatenated genomes and their individual segments revealed that established sequences from the northeast Pacific were monophyletic in all analyses. Bayesian inference phylogenetic trees of S1 sequences using BEAST and MrBayes also found that sequences from the northeast Pacific grouped separately from sequences from other areas. One PRV-1 sample (WCAN_BC17_AS_2017) from an escaped Atlantic salmon, collected in British Columbia but derived from Icelandic broodstock, grouped with other S1 sequences from Iceland. Our concatenated genome and S1 analysis demonstrated that PRV-1 from the northeast Pacific is genetically distinct but descended from PRV-1 from the North Atlantic. However, the analyses were inconclusive as to the timing and exact source of introduction into the northeast Pacific, either from eastern North America or from European waters of the North Atlantic. There was no evidence that PRV-1 was evolving differently between free-ranging Pacific Salmon and farmed Atlantic Salmon. The northeast Pacific PRV-1 sequences fall within genogroup II based on the classification of Garseth, Ekrem, and Biering (Garseth, A. H., Ekrem, T., and Biering, E. (2013) ‘Phylogenetic Evidence of Long Distance Dispersal and Transmission of Piscine Reovirus (PRV) between Farmed and Wild Atlantic Salmon’, PLoS One, 8: e82202.), which also includes North Atlantic sequences from Eastern Canada, Iceland, and Norway. The additional full-genome sequences herein strengthen our understanding of phylogeographical patterns related to the northeast Pacific, but a more balanced representation of full PRV-1 genomes from across its range, as well additional sequencing of archived samples, is still needed to better understand global relationships including potential transmission links among regions.

Closing the Gap: Results of the Multicenter Canadian Randomized Controlled Trial of Structured Transition in Young Adults With Type 1 Diabetes

OBJECTIVE

To determine if a structured transition program for young adults with type 1 diabetes improves clinic attendance, glycemic control, diabetes-related distress, quality of life, and satisfaction with care.

RESEARCH DESIGN AND METHODS

In this multicenter randomized controlled trial, young adults (17-20 years) with type 1 diabetes were randomly assigned to a transition program with a transition coordinator or to standard care. The intervention lasted 18 months (6 in pediatric and 12 in adult care). The primary outcome was the proportion of participants who failed to attend at least one adult diabetes clinic visit during the 12-month follow-up after completion of the intervention.

RESULTS

We randomized 205 participants, 104 to the transition program and 101 to standard care. Clinic attendance was improved in the transition program (mean [SD] number of visits 4.1 [1.1] vs. 3.6 [1.2], P = 0.002), and there was greater satisfaction with care (mean [SD] score 29.0 [2.7] vs. 27.9 [3.4], P = 0.032) and less diabetes-related distress (mean [SD] score 1.9 [0.8] vs. 2.1 [0.8], P = 0.049) reported than in standard care. There was a trend toward improvement in mean HbA_1c (8.33% [68 mmol/mol] vs. 8.80% [73 mmol/mol], P = 0.057). During the 12-month follow-up, there was no difference in those failing to attend at least one clinic visit (P = 0.846), and the mean change in HbA_1c did not differ between the groups (P = 0.073). At completion of follow-up, the groups did not differ with respect to satisfaction with care or diabetes-related distress and quality of life.

CONCLUSIONS

Transition support during this 18-month intervention was associated with increased clinic attendance, improved satisfaction with care, and decreased diabetes-related distress, but these benefits were not sustained 12 months after completion of the intervention.

The association between platelet dysfunction and adverse outcomes in cardiac surgical patients

Haemostatic activation during cardiopulmonary bypass is associated with prothrombotic complications. Although it is not possible to detect and quantify haemostatic activation directly, platelet dysfunction, as measured with point-of-care-assays, may be a useful surrogate. In this study, we assessed the association between cardiopulmonary bypass-associated platelet dysfunction and adverse outcomes in 3010 cardiac surgical patients. Platelet dysfunction, as measured near the end of the rewarming phase of cardiopulmonary bypass, was calculated as the proportion of non-functional platelets after activation with collagen. Logistic regression and multivariable analyses were applied to assess the relationship between platelet dysfunction and a composite of in-hospital death; myocardial infarction; stroke; deep vein thrombosis or pulmonary embolism; and acute kidney injury (greater than a two-fold increase in creatinine). The outcome occurred in 251 (8%) of 3010 patients. The median (IQR [range]) percentage platelet dysfunction was less for those without the outcome as compared with those with the outcome; 14% (8-28% [1-99%]) vs. 19% (11-45% [2-98%]), p < 0.001. After risk adjustment, platelet dysfunction was independently associated with the composite outcome (p < 0.001), such that for each 1% increase in platelet dysfunction there was an approximately 1% increase in the composite outcome (OR 1.012; 95%CI 1.006-1.018). This exploratory study suggests that cardiopulmonary bypass-associated platelet dysfunction has prognostic value and may be a useful clinical measure of haemostatic activation in cardiac surgery.

Should learners reason one step at a time? A randomised trial of two diagnostic scheme designs

CONTEXT

Making a diagnosis can be difficult for learners as they must integrate multiple clinical variables. Diagnostic schemes can help learners with this complex task. A diagnostic scheme is an algorithm that organises possible diagnoses by assigning signs or symptoms (e.g. systolic murmur) to groups of similar diagnoses (e.g. aortic stenosis and aortic sclerosis) and provides distinguishing features to help discriminate between similar diagnoses (e.g. carotid pulse). The current literature does not identify whether scheme layouts should guide learners to reason one step at a time in a terminally branching scheme or weigh multiple variables simultaneously in a hybrid scheme. We compared diagnostic accuracy, perceptual errors and cognitive load using two scheme layouts for cardiac auscultation.

METHODS

Focused on the task of identifying murmurs on Harvey, a cardiopulmonary simulator, 86 internal medicine residents used two scheme layouts. The terminally branching scheme organised the information into single variable decisions. The hybrid scheme combined single variable decisions with a chart integrating multiple distinguishing features. Using a crossover design, participants completed one set of murmurs (diastolic or systolic) with either the terminally branching or the hybrid scheme. The second set of murmurs was completed with the other scheme. A repeated measures manova was performed to compare diagnostic accuracy, perceptual errors and cognitive load between the scheme layouts.

RESULTS

There was a main effect of the scheme layout (Wilks' λ = 0.841, F_3,80 = 5.1, p = 0.003). Use of a terminally branching scheme was associated with increased diagnostic accuracy (65 versus 53%, p = 0.02), fewer perceptual errors (0.61 versus 0.98 errors, p = 0.001) and lower cognitive load (3.1 versus 3.5/7, p = 0.023).

CONCLUSIONS

The terminally branching scheme was associated with improved diagnostic accuracy, fewer perceptual errors and lower cognitive load, suggesting that terminally branching schemes are effective for improving diagnostic accuracy. These findings can inform the design of schemes and other clinical decision aids.

Critical care provision after colorectal cancer surgery

BACKGROUND

Colorectal cancer (CRC) is the 2nd largest cause of cancer related mortality in the UK with 40 000 new patients being diagnosed each year. Complications of CRC surgery can occur in the perioperative period that leads to the requirement of organ support. The aim of this study was to identify pre-operative risk factors that increased the likelihood of this occurring.

METHODS

This is a retrospective observational study of all 6441 patients who underwent colorectal cancer surgery within the West of Scotland Region between 2005 and 2011. Logistic regression was employed to determine factors associated with receiving postoperative organ support.

RESULTS

A total of 610 (9 %) patients received organ support. Multivariate analysis identified age ≥65, male gender, emergency surgery, social deprivation, heart failure and type II diabetes as being independently associated with organ support postoperatively. After adjusting for demographic and clinical factors, patients with metastatic disease appeared less likely to receive organ support (p = 0.012).

CONCLUSIONS

Nearly one in ten patients undergoing CRC surgery receive organ support in the post operative period. We identified several risk factors which increase the likelihood of receiving organ support post operatively. This is relevant when consenting patients about the risks of CRC surgery.

Scalded Skin Syndrome Caused by a Methicillin Sensitive Staphylococcus aureus of a type not commonly associated with exfoliative toxins in Scotland

A three-year-old boy was admitted to the hospital with a three-day history of chickenpox and a one-day history of fever and enlarging skin lesions on his chest, trunk, and around his neck. The lesions were enlarged and skin peeling over the chest wall was noted. Despite starting him on Flucloxacillin/Aciclovir, new lesions were noted with blisters over chest, legs, arms and buttocks. A clinical diagnosis of Staphylococcal Scalded Skin Syndrome (SSSS) was made and laboratory results confirmed Methicillin sensitive Staphylococcus aureus (MRSA) isolation. The isolates were sent to Scottish MRSA reference lab (SMRSARL) for typing and toxin detection. The isolate from this child was positive for the exfoliative toxin A (eta) gene and negative for exfoliative toxin B, toxic shock syndrome toxin, panton-valentine leukocidin and entertoxins A, B, C, D, E. By Pulse Field Gel Electrophoresis (PFGE) this isolate was identified as MLST Type 88 clone which has been associated with skin lesions in other countries.

Associated systemic and ocular disorders in patients with congenital unilateral cataracts: the Infant Aphakia Treatment Study experience

PurposeFive-year prospective data on children enrolled in the Infant Aphakia Treatment Study (IATS) provided an opportunity to explore ocular and systemic associations in patients with a unilateral congenital cataract.MethodsInfants <7 months of age with a unilateral cataract were eligible for IATS screening. We reviewed data pertaining to the exclusion of patients as well as data collected on standardized study forms used at any time for documentation of ocular or systemic disorders.ResultsOverall, 227 infants were referred for possible enrollment. Of these, 10 had insignificant cataracts and 32 refused to participate. Of those excluded, 3 were premature, 27 had significant ocular disease (usually persistent fetal vasculature (PFV) or corneal diameter <9 mm), and 4 had systemic disorders. An additional 26 were excluded at the time of the first EUA, most often because of PFV or variants thereof. On follow-up, in the 114 enrolled patients, the following disorders were diagnosed: Stickler syndrome (1), mitochondrial disease (1), autism (1), and presumed congenital rubella syndrome (1). No patient developed a cataract in the fellow eye.DiscussionSome conditions that can feature unilateral cataracts are diagnosed at birth or very early in life, but others may be diagnosed at varying periods thereafter. PFV and its variants are the most common associated ocular findings in about a quarter of cases of unilateral congenital cataracts.ConclusionAlthough patients with a unilateral cataract may have significant associated abnormalities in the affected eye, most commonly PFV and its variants, the prevalence of associated significant systemic disease is quite low.

Findings from a pilot Randomised trial of an Asthma Internet Self-management Intervention (RAISIN)

OBJECTIVE

To evaluate the feasibility of a phase 3 randomised controlled trial (RCT) of a website (Living Well with Asthma) to support self-management.

DESIGN AND SETTING

Phase 2, parallel group, RCT, participants recruited from 20 general practices across Glasgow, UK. Randomisation through automated voice response, after baseline data collection, to website access for minimum 12 weeks or usual care.

PARTICIPANTS

Adults (age≥16 years) with physician diagnosed, symptomatic asthma (Asthma Control Questionnaire (ACQ) score ≥1). People with unstable asthma or other lung disease were excluded.

INTERVENTION

'Living Well with Asthma' is a desktop/laptop compatible interactive website designed with input from asthma/ behaviour change specialists, and adults with asthma. It aims to support optimal medication management, promote use of action plans, encourage attendance at asthma reviews and increase physical activity.

OUTCOME MEASURES

Primary outcomes were recruitment/retention, website use, ACQ and mini-Asthma Quality of Life Questionnaire (AQLQ). Secondary outcomes included patient activation, prescribing, adherence, spirometry, lung inflammation and health service contacts after 12 weeks. Blinding postrandomisation was not possible.

RESULTS

Recruitment target met. 51 participants randomised (25 intervention group). Age range 16-78 years; 75% female; 28% from most deprived quintile. 45/51 (88%; 20 intervention group) followed up. 19 (76% of the intervention group) used the website, for a mean of 18 min (range 0-49). 17 went beyond the 2 'core' modules. Median number of logins was 1 (IQR 1-2, range 0-7). No significant difference in the prespecified primary efficacy measures of ACQ scores (-0.36; 95% CI -0.96 to 0.23; p=0.225), and mini-AQLQ scores (0.38; -0.13 to 0.89; p=0.136). No adverse events.

CONCLUSIONS

Recruitment and retention confirmed feasibility; trends to improved outcomes suggest use of Living Well with Asthma may improve self-management in adults with asthma and merits further development followed by investigation in a phase 3 trial.

TRIAL REGISTRATION NUMBER

ISRCTN78556552; Results.

1000 Port-A-Cath ® placements by subclavian vein approach: single surgeon experience

INTRODUCTION

Totally implantable venous access ports are widely used for the administration of chemotherapy in patients with cancer. Although there are several approaches to implantation, here we describe Port-A-Cath(®) (PAC) placement by percutaneous puncture of the subclavian vein with ultrasonographic guidance.

PATIENTS AND METHODS

Data on our vascular access service were collected prospectively from June 2004. This service included port-a-caths and Hickman lines. Once 1000 consecutive port-a-caths(®) had been reached the study was closed and data analysed for the port-a-caths(®) alone. The left subclavian vein was the preferred site for venous access, with the right subclavian and jugular veins being the alternative choices if the initial approach failed. Patients were followed up in the short-term, and all the procedures were carried out by a single surgeon at each one of two institutions.

RESULTS

Venous access by PAC was established in 100 % of the 1,000 cases. Of the 952 patients where the left subclavian vein was chosen for the first attempt of puncture, the success rate of PAC placement was 95 % (n = 904). Pneumothorax occurred in 12 patients (1.2 %), and a wound haematoma occurred in 4 (0.4 %) out of the total 1,000 patients. No infections were recorded during the immediate post-operative period but only in the long-term post-operative use with 8 patients requiring removal of the PAC due to infection following administration of chemotherapy.

CONCLUSION

This is a very large series of PAC placement with an ultrasound-guided approach for left subclavian vein and X-ray confirmation, performed by a single surgeon, demonstrating both the safety and effectiveness of the procedure.

Is lower socioeconomic status associated with more advanced thyroid cancer stage at presentation? A study in two Canadian centers

BACKGROUND

Some studies have shown a higher incidence of thyroid cancer in patients with insurance coverage and higher socioeconomic status (SES), and a higher thyroid cancer stage in patients with lower SES, suggesting SES-related health disparity in thyroid cancer. However, it is not known if the same is evident under a universal healthcare system such as that in Canada.

METHODS

We used data from the Canadian Thyroid Cancer Consortium, a large thyroid cancer registry that collects data from two major thyroid cancer referral centers (London, Ontario, and Halifax, Nova Scotia). We included patients who presented with thyroid cancer between 1998 and 2011. We determined age at presentation, sex, and thyroid cancer status using the American Joint Committee on Cancer (AJCC) staging criteria. Individuals' postal codes were used to retrieve data from the Canadian census for the years 1996, 2001, and 2006 to approximate household income. Ordered logistic regression was used to determine odds ratios of presenting with more advanced stage thyroid cancer as they relate to income, age, and sex.

RESULTS

We included 1701 patients: 1334 cases from London and 367 from Halifax. Thyroid cancer was diagnosed more frequently in the higher SES groups (p<0.001). Compared to patients in the top income quintile, patients in the lowest and second-lowest income quintiles had significantly higher odds of having more advanced stage thyroid cancer at presentation (OR 1.58, p=0.002; 1.37, p=0.024 respectively).

CONCLUSIONS

Our study suggests that, similar to countries that lack a universal healthcare system, health disparity in thyroid cancer also exists in Canada. It appears that while thyroid cancers were diagnosed more frequently in Canadian patients of higher SES, Canadian patients in the lower SES groups had more advanced stage thyroid cancer at presentation.

Mental health in female veterinarians: effects of working hours and having children

BACKGROUND

Personal, interpersonal and organisational factors have been suggested as possible causes of stress, anxiety and depression for veterinarians. We used established psychological scales to measure (1) levels of distress and work-related stress (anxiety and depression) and (2) the demographic and work characteristics of female veterinarians in relation to anxiety, depression and mental health.

METHODS

A national cross-sectional survey of a cohort population was conducted and self-administered questionnaires were received from 1017 female veterinarians who completed the mental health section of the survey. Using linear and logistic regression analyses, we examined demographic and work-related factors associated with overall stress measured by the General Health Questionnaire scale and the Affective Well-Being scale (Anxiety-Contentment Axis and Depression-Enthusiasm Axis).

RESULTS

More than one-third (37%) of the sample was suffering 'minor psychological distress', suggesting the stressful nature of veterinary practice. Women with two or more children had less anxiety and depression compared with those who had never been pregnant or were childless. Longer working hours were associated with increased anxiety and depression in female veterinarians overall and in stratified samples of women with and without children.

CONCLUSION

Among the work characteristics of veterinary practice, long working hours may have a direct effect on a veterinarian's health in terms of anxiety, depression and mental health. The finding also indicates that women with two or more children have less anxiety and depression than women who have never been pregnant or childless women.

Kinetics of transient hiatus hernia during transient lower esophageal sphincter relaxations and swallows in healthy subjects

BACKGROUND

Proximal displacement of the gastro-esophageal junction (GEJ) is present in hiatus hernia but also occurs transiently during transient lower esophageal sphincter relaxations (TLESRs) and swallows. Using a novel magnetic-based technique we have performed detailed examination of the GEJ movement during TLESRs and swallows in healthy subjects.

METHODS

In 12 subjects, a magnet was endoscopically clipped to the GEJ and combined assembly of Hall-Effect locator probe and 36 channel high-resolution manometer passed nasally. After a test meal the subjects were studied for 90 min.

KEY RESULTS

The median amplitude of proximal movement of GEJ during TLESRs was 4.3 cm (1.6-8.8 cm) and this was substantially greater than during swallowing at 1.2 cm (0.4-2.7 cm), P = 0.002. With both TLESRs and swallows proximal GEJ movement coincided with lower esophageal sphincter (LES) relaxation and return to its original position occurred 4 s after return of LES tone. Kinetic modeling of the movement of the GEJ during TLESRs indicated two return phases with the initial return phase having the greater velocity (0.9 cm s(-1) ) and being strongly correlated with amplitude of proximal movement (r = 0.8, P < 0.001).

CONCLUSIONS & INFERENCES

The marked proximal GEJ migration during TLESRs represents very severe herniation of the GEJ. The rapid initial return of the GEJ following TLESRs when the crural diaphragm is relaxed and its correlation with amplitude suggest it is due to elastic recoil of the phreno-esophageal ligament. The marked stretching of the phreno-esophageal ligament during TLESRs may contribute to its weakening and development of established hiatus hernia.

Voyager 2 in the uranian system: imaging science results

Voyager 2 images of the southern hemisphere of Uranus indicate that submicrometersize haze particles and particles of a methane condensation cloud produce faint patterns in the atmosphere. The alignment of the cloud bands is similar to that of bands on Jupiter and Saturn, but the zonal winds are nearly opposite. At mid-latitudes (-70 degrees to -27 degrees ), where winds were measured, the atmosphere rotates faster than the magnetic field; however, the rotation rate of the atmosphere decreases toward the equator, so that the two probably corotate at about -20 degrees . Voyager images confirm the extremely low albedo of the ring particles. High phase angle images reveal on the order of 10(2) new ringlike features of very low optical depth and relatively high dust abundance interspersed within the main rings, as well as a broad, diffuse, low optical depth ring just inside the main rings system. Nine of the newly discovered small satellites (40 to 165 kilometers in diameter) orbit between the rings and Miranda; the tenth is within the ring system. Two of these small objects may gravitationally confine the e ring. Oberon and Umbriel have heavily cratered surfaces resembling the ancient cratered highlands of Earth's moon, although Umbriel is almost completely covered with uniform dark material, which perhaps indicates some ongoing process. Titania and Ariel show crater populations different from those on Oberon and Umbriel; these were probably generated by collisions with debris confined to their orbits. Titania and Ariel also show many extensional fault systems; Ariel shows strong evidence for the presence of extrusive material. About halfof Miranda's surface is relatively bland, old, cratered terrain. The remainder comprises three large regions of younger terrain, each rectangular to ovoid in plan, that display complex sets of parallel and intersecting scarps and ridges as well as numerous outcrops of bright and dark materials, perhaps suggesting some exotic composition.

Association between the CYP1A1 gene polymorphism and susceptibility to emphysema and lung cancer

Aim-To investigate cytochrome P4501A1 (CYP1A1) polymorphism and susceptibility to emphysema and lung cancer.Methods-A novel polymerase chain reaction (PCR) for genotyping the CYP1A1 polymorphism, corresponding to putative low or high enzyme activity, was developed to genotype lung cancer resection samples which had been assessed macroscopically for the presence of centriacinar and panacinar emphysema. Samples were collected and genotyped from a group of patients with chronic obstructive airways disease. A control group of anonymous blood donations was genotyped to determine the basal levels of the polymorphism in the Scottish population.Results-The high activity allele of the CYP1A1 gene is associated with susceptibility to centriacinar emphysema and lung cancer but not panacinar emphysema. CYP1A1 polymorphism is not linked to lung cancer in the absence of emphysema, nor to chronic obstructive airways disease which is the clinical manifestation of emphysema, particularly of the panacinar type.Conclusions-Susceptibility to emphysema and lung cancer is associated with polymorphism of the P4501A1 gene. A trend towards damage of centriacinar pattern has been detected, which supports the theory that centriacinar emphysema results from local, direct damage to the respiratory bronchioles from exposure to cigarette smoke.

Shift in sleep apnoea type in heart failure patients in the CANPAP trial

In patients with heart failure (HF), the predominant type of sleep apnoea can change over time in association with alterations in circulation time. The aim of this study was to determine whether, in some patients with HF, a spontaneous shift from mainly central (>50% central events) to mainly obstructive (>50% obstructive events) sleep apnoea (CSA and OSA, respectively) over time coincides with improvement in left ventricular ejection fraction (LVEF). Therefore, sleep studies and LVEFs of HF patients with CSA from the control arm of the Canadian Continuous Positive Airway Pressure for Patients with Central Sleep Apnea and Heart Failure (CANPAP) trial were examined to determine whether some converted to mainly OSA and, if so, whether this was associated with an increase in LVEF. Of 98 patients with follow-up sleep studies and LVEFs, 18 converted spontaneously to predominantly OSA. Compared with those in the nonconversion group, those in the conversion group had a significantly greater increase in the LVEF (2.8% versus -0.07%) and a significantly greater fall in the lung-to-ear circulation time (-7.6 s versus 0.6 s). In patients with HF, spontaneous conversion from predominantly CSA to OSA is associated with an improvement in left ventricular systolic function. Future studies will be necessary to further examine this relationship.

Long-term cost-effectiveness of weight management in primary care

BACKGROUND

As obesity prevalence and health-care costs increase, Health Care providers must prevent and manage obesity cost-effectively.

METHODS

Using the 2006 NICE obesity health economic model, a primary care weight management programme (Counterweight) was analysed, evaluating costs and outcomes associated with weight gain for three obesity-related conditions (type 2 diabetes, coronary heart disease, colon cancer). Sensitivity analyses examined different scenarios of weight loss and background (untreated) weight gain.

RESULTS

Mean weight changes in Counterweight attenders was -3 kg and -2.3 kg at 12 and 24 months, both 4 kg below the expected 1 kg/year background weight gain. Counterweight delivery cost was pound59.83 per patient entered. Even assuming drop-outs/non-attenders at 12 months (55%) lost no weight and gained at the background rate, Counterweight was 'dominant' (cost-saving) under 'base-case scenario', where 12-month achieved weight loss was entirely regained over the next 2 years, returning to the expected background weight gain of 1 kg/year. Quality-adjusted Life-Year cost was pound2017 where background weight gain was limited to 0.5 kg/year, and pound2651 at 0.3 kg/year. Under a 'best-case scenario', where weights of 12-month-attenders were assumed thereafter to rise at the background rate, 4 kg below non-intervention trajectory (very close to the observed weight change), Counterweight remained 'dominant' with background weight gains 1 kg, 0.5 kg or 0.3 kg/year.

CONCLUSION

Weight management for obesity in primary care is highly cost-effective even considering only three clinical consequences. Reduced healthcare resources use could offset the total cost of providing the Counterweight Programme, as well as bringing multiple health and Quality of Life benefits.

Oesophageal and gastric intestinal-type adenocarcinomas show the same male predominance due to a 17 year delayed development in females

BACKGROUND AND AIMS

Upper gastrointestinal adenocarcinomas show an unexplained male predominance that is more apparent in oesophagus than stomach and in intestinal than diffuse histological subtype. We have conducted a population-based study to determine whether the gender phenomenon is primarily related to the anatomical site or the histological subtype.

METHOD AND MATERIALS

Of 3270 gastric and oesophageal cancers recorded in the West of Scotland Cancer Registry, 1998-2002, 812 were randomly selected for detailed analysis. The Lauren histological subtype of adenocarcinoma was determined by reviewing 1204 original reports and 3241 biopsies.

RESULTS

Analysis included 405 non-cardia cancers, 173 cardia cancers and 209 oesophageal adenocarcinomas. Crude incidence rate of intestinal subtype was higher in males (23.86/100,000 person-years) versus females (9.00/100,000 person-years), giving a male/female (M/F) ratio of 2.65 whereas diffuse subtype was similar for both genders (5.58 vs 5.20/100,000 person-years) yielding M/F of 1.07. The M/F ratios for oesophageal, cardia and non-cardia gastric cancer were 3.5, 2.0 and 1.6, respectively. Multiple logistic regression indicated that the odds of male gender was related to the histological subtype rather than anatomical location (odds ratio 2.6, 95% confidence interval 1.78 to 3.9). Curve fitting of the age-specific incidence of intestinal subtype indicated that similar functions describe the rise in incidence with age in males and in females. However, the age-specific incidence of female intestinal subtype was delayed by 17.3 years. The M/F ratio of intestinal subtype was 3.41 at age <50 years, peaked at 7.86 at age 50-59 years and then showed a progressive decrease after 50-60 years of age.

CONCLUSION

Male predominance of upper gastrointestinal adenocarcinoma is related to the intestinal histological subtype rather than tumour location and is due to marked delayed development of this subtype in females prior to 50-60 years of age.

Usefulness of mec-associated direct repeat unit (dru) typing in the epidemiological analysis of highly clonal methicillin-resistant Staphylococcus aureus in Scotland

The incidence of the epidemic methicillin-resistant Staphylococcus aureus (EMRSA) strains EMRSA-15 and EMRSA-16 in Scotland has increased dramatically, now accounting for c. 70% and c. 20% of isolates, respectively. Epidemiological tracking of these EMRSA strains is difficult, as c. 50% of EMRSA-15 and c. 35% of EMRSA-16 isolates are indistinguishable using pulsed-field gel electrophoresis (PFGE) and other typing methods. The usefulness of mec-associated direct repeat unit (dru) sequence analysis as a more sensitive approach to tracking the persistence and spread of these 'clonal' EMRSA strains in Scotland was evaluated. Analysis of 47 EMRSA-15 and 57 EMRSA-16 isolates (including two separately cultured isolates of the Harmony collection type strain) obtained from 22 hospital laboratories over an 8-year period (1997-2005) revealed 13 and 12 different dru types, respectively. Whereas some types appeared to be endemic in multiple hospitals, subtypes that may represent specific strain movement among hospitals in a given geographical region were identified in other instances. These results suggest that mec-associated dru typing may have potential for identifying and tracking specific subtypes of otherwise indistinguishable epidemic MRSA isolates such as those in Scotland.

Suppression of high-p{T} neutral pion production in central Pb+Pb collisions at sqrt[S{NN}]=17.3 GeV relative to p+C and p+Pb collisions

Neutral pion transverse momentum spectra were measured in p+C and p+Pb collisions at sqrt[S{NN}]=17.4 GeV at midrapidity (2.3 less than or approximately equal eta{lab} less than or approximately equal 3.0) over the range 0.7 less than or approximately equal p{T} less than or approximately equal 3.5 GeV/c. The spectra are compared to pi{0} spectra measured in Pb+Pb collisions at sqrt[S{NN}]=17.3 GeV in the same experiment. For a wide range of Pb+Pb centralities (N{part} less than or approximately equal 300), the yield of pi{0}'s with p{T} greater than or approximately equal 2 GeV/c is larger than or consistent with the p+C or p+Pb yields scaled with the number of nucleon-nucleon collisions (N{coll}), while for central Pb+Pb collisions with N{part}greater than or approximately equal 350, the pi{0} yield is suppressed.

Oral opioids for chronic non-cancer pain: higher prevalence of hypogonadism in men than in women

The effect of chronic oral opioids on hypothalamus-pituitary-gonadal axis in women, and on bone mineral density (BMD) in men and women is not known. The objective of this cross-sectional study was to determine the effect of long-term oral opioids on gonadal status and BMD in male and female patients with chronic non-cancer pain (CNCP). We included 26 community-dwelling CNCP patients, 12 men and 14 premenopausal women, treated with oral opioids for at least one year. We obtained Visual Analogue Scale for pain score, BMD and plasma LH and FSH in all patients; menstrual history and estradiol in women; free androgen index and total and free testosterone in men. Men were older then women (p<0.05) and had used opioids for a longer period (7.2+/-3.8 and 4.1+/-1.8 years, respectively; p<0.05), but there was no difference in opioid dose or pain score between sexes. The prevalence of hypogonadism was high in men (75%), while only 21% of the women reported oligo- or amenorrhea indicating hypogonadism (P<0.01, between sexes). Osteopenia was found in 50% of men and 21% of women (p=NS). We conclude that in CNCP patients receiving chronic opioid therapy there is a much higher prevalence of hypogonadism in men then in women. This needs to be considered clinical practice.